Pilot Flies at Night in a Solar-Powered Plane

A pioneering pilot is flying at night, after flying all through the day. The catch? He is in the cockpit of a solar-powered plane, with the aim of flying through the night until the sun rises Thursday. So far, pilot Andre Borschberg awaits dawn aboard the Solar Impulse HB-SIA aircraft.

Propellers whirred on the slim airplane's long wings as Swiss pilot Andre Borschberg set out to make history by flying a solar-powered airplane through day and night, without fuel.

Speaking through a headset from the cockpit after takeoff Wednesday morning in Payerne, Switzerland, Borschberg could barely contain a smile.

"It was very special, you know. That's the moment, I think, that everybody has been waiting for since now almost seven years and thinking about it -- I don't want to say every day -- but almost. That's a very, very important milestone for the project. I guess everybody was excited, but I was very excited, too," he said.

The Solar Impulse HB-SIA is a single-seater, solar-powered plane. Its wings are as long as those of an Airbus A340 -- a whopping 63 meters -- and the top side of those wings are covered with a skin of solar cells. During daylight hours Wednesday, the plane took in the sun's rays though 12,000 solar panels and charged the plane's 400 kilograms of batteries.

The goal is for plane to keep its motors running through the night using the energy stored inside those batteries.

Borschberg said he was thrilled to be in the cockpit of a plane that was producing more energy than it was consuming. And he is not simply the pilot for this solar-powered mission. He is also Solar Impulse's chief executive officer.

The mission has not been without its setbacks. The Solar Impulse team had planned for a night flight last week, but they had to postpone that takeoff when a critical piece of equipment malfunctioned. At that time, the founders of the project, Borschberg and Bertrand Piccard, expressed their disappointment as well as their hope.

"You have to understand that the airplane is completely experimental. It is the type of airplane that has never flown in the past, so we need to assist the pilot from the ground, but we also need to assist the airplane itself," said Solar Impulse Chairman Piccard.

He explained that high-tech equipment transmits data from the plane to a team on the ground. That equipment, like everything on the 1,600 kilogram aircraft, is lightweight. And, he added, the equipment records, in his words, "absolutely everything." "The team will know about vibrations in the wings, about the position of the flight controls, about the efficiency of the solar cells, all the energy that gets in, all the energy that gets out," he said.

Piccard initiated the project in 1999, setting his sights on such solar-powered flight after he circumnavigated the world in a balloon. He said the Solar Impulse illustrates the potential of clean technologies and renewable energy.

The Solar Impulse team says Borschberg and the carbon fiber plane spent all day Wednesday slowly ascending to an altitude of 8,700 meters -- 200 meters higher than planned. Roughly two hours before sunset Wednesday evening, the sun's rays were no longer strong enough to supply the solar cells with energy. As planned, the plane began a slow descent, with the goal of maintaining an altitude of 1,500 meters until sunrise.

In its test flights, the plane managed to stay aloft for 14 hours. It has already surpassed that record with this flight.

And, if the mission is successful, the Solar Impulse HB-SIA will be the first plane to ever harness the power of the sun to fly through the night.